| 摘要: | 目的：探討人體進行離心運動引起肌肉損傷 (exercise-induced muscle damage, EIMD) 前，進行低強度跑步運動對跑步經濟性、跳躍及靜態平衡等指標的影響。方法：召募16名大學健康男性做為研究對象，並以前測最大攝氧量值做為隨機分組方式，分派至低強度跑步 (low-intensity running, LLR) 或控制 (control, CON) 組之中 (每組n=8)。LLR組雙腿分別在進行膝伸與屈肌群1回合100次最大等速離心收縮 (MAX; 60°/s) 前1.2小時，以50%VO2max強度進行1回合1小時水平坡度跑步，CON組僅進行與LLR組相同的MAX。在進行1小時跑步運動的前與後，進行身體肌肉表層溫度 (BST)、核心溫度 (CT)、超音波血流攝像 [動脈平均血流量 (MBF)] 測量。肌肉損傷指標 [最大等長肌力 (MVC)、肌肉酸痛 (SOR)]、跳躍表現 [蹲踞跳 (squat jump, SJ)、下蹲跳 (countermovement jump, CMJ) 及著地反彈跳 (drop jump, DJ)、靜態平衡表現 (閉眼單腳站立) 均安排在MAX前、後第0-5天、7及10天各測一次。跑步經濟性 [攝氧量 (oxygen consumption, VO2)] 則安排在MAX前、後第2、5及10天，以90%VO2max強度進行1回合5分鐘水平坡度跑步各測一次。所有依變項資料以二因子混合設計變異數分析進行統計分析。結果：發現LLR組進行1小時跑步後，CBT、MBF均產生顯著的提高 (p<.05)；不同兩組在進行MAX之後，其引起肌肉損傷 (MVC、SOR) 程度、跑步經濟性 (VO2) 變差以及跳躍 (SJ、CMJ及DJ高度) 與平衡表現 (CoP平均偏移速度及面積增加) 下降情形，LLR組皆顯著低於CON組 (p<.05)。結論：本研究結果顯示，在EIMD前，進行低強度跑步運動引起體溫及血液流量顯著提高下，可減輕隨後進行EIMD的症狀，進而使跑步經濟性、跳躍及靜態平衡下降程度變小。因此，在EIMD前讓研究對象進行可顯著提升體溫及血液流量之低強度跑步運動，似乎可做為一種預防降低人體雙腿進行EIMD之方法。
Purpose: This study investigated the effects of the low-intensity running exercise (LLR) on the indices of exercise-induced muscle damage (EIMD), running economy, jump and static balance of lower extremities before eccentric EIMD. Methods: Sixteen healthy young untrained men were randomly assigned into LLR or CON group (n=8, per group) by their pre-determined maximal oxygen capacity (VO2max). The LLR group performed a bout of 100 maximal isokinetic (60°/s) eccentric contractions (MAX) of each knee extensors and flexors, by counterbalance, at 1.2 h after performing a bout of 60-min low-intensity of level running (50%VO2max). The CON group performed the same MAX, as the LLR group, without a prior bout of running exercise. Body surface temperature (BST), core temperature (CT), mean blood flow at femoral artery of ultrasound imaging (MBF) were measured immediately before and after low-intensity running for the LLR group. Muscle damage indicators [maximal isometric strength (MVC), muscle soreness (SOR)], jump [squat jump (SJ), countermovement jump (CMJ), and drop jump (DJ)], static balance index (SBI) measures were taken before, 0~5, 7 and 10 days after MAX. Running economy (RE) parameters [oxygen consumption (VO2)], using a bout of 5-min level running at 90%VO2max, were assessed before, 2, 5, and 10 days after MAX. Changes in each measure from MAX between the groups were compared by a mixed-design of two-way ANOVA. Results: Significantly (p<.05) increases in BCT and MBF immediately after 1-h running compared to baseline for the LLR group were observed. Changes in the all indicators of muscle damage, RE, jump, and balance after MAX for both groups were significantly differences compared to baseline. The changes in all measures after MAX for the LLR group were significantly smaller than the CON group. Conclusion: These results showed that protective effect of muscle damage, RE, jump, and balance conferred by a bout of low-intensity running against a subsequent bout of MAX. Therefore, a bout of low-intensity running could be regarded as one of efficient preventive measures to reduce EIMD of both knee extensors and flexors, jump, and balance performances. |
